Lloyd John Old (São Francisco, Califórnia, 23 de setembro de 1933 – Nova Iorque, 28 de novembro de 2011) foi um imunologista estadunidense.
Elizabeth Carswell, Lloyd J. Old et al.: An endotoxin-induced serum factor that causes necrosis of tumors. In: PNAS, Volume 72, Nr. 9 , 1975, p. 3666–3670, doi:10.1073/pnas.72.9.3666
Der Tumornekrosefaktor. In: Spektrum der Wissenschaft, julho de 1988
Padmanee Sharma, James P. Allison: Lloyd. J. Old (1933–2011). In: Science, Band 335, Nr. 6064, 2012, S. 49, DOI:10.1126/science.1217940, Volltext
Paul Vitello: Lloyd J. Old, Champion of Using Cells to Fight Illness, Dies at 78. In: The New York Times, 4 de dezembro de 2011.
Cancer Research Institute: Lloyd J. Old, M.D., Father of Modern Tumor Immunology
Memorial Sloan-Kettering Cancer Center: Lloyd Old, MD
Memorial Sloan-Kettering Cancer Center: Harnessing the Immune System to Help the Body Fight Cancer